/* avoid.c */void random_avoid() {    backward(); sleep(.4);    set_beeper_pitch(1000.); beeper_on();    if (random(2) == 0) left();    else right();    sleep((float)random(100)/100. + .5);    beeper_off();}void left_avoid() {    backward(); sleep(.4);    right(); sleep(.4);}void right_avoid() {    backward(); sleep(.4);    left(); sleep(.4);}